Controlling cam



March 27, 1951 v PEDERSEN 2,546,560

CONTROLLING CAM Filed Jan. 25, 1946 2 Sheets-Sheet l March 27, 1951 H.v. F. PEDERSEN CONTROLLING CAM 2 Sheets-Sheet 2 Filed Jan. 25, 1946INVENTOR. H. 1 Pads/-53 Patented Mar. 27, 1951 CONTROLLING CAM HansViihelm Flygel Pedersen, Copenhagen,

Denmark Application January 25, 1946, Serial No. 643,432

' In Denmark March 18, 1941 Section 1, Public Law 69%), August 8, 1946Patent expires March 18, 196i.

Claims.

This invention relates to a composite controlling cam, especiallyintended for controlling fuel pumps or valves in reversible internalcombustion engines, and the invention aims at shaping such a controllingcam so that it may be advantageously employed for both directions ofrotation of the engine.

In reversible engines it was formerly the practies for one and the samefuel pump to have two different controllin cams fitted closely besideeach other on the cam shaft, one controlling cam being only intended forthe working of the engine in one direction, the other only for theworking in the other direction. At reversing, the camshaft was shiftedlongitudinally, whereby at the same time the roller of the fuel pumpintended for co-operation with the controlling cam had to be raised fromthe controlling cam that had till then been in action, in order that theother controlling cam might unhindered pass in under the roller at theshifting of the camshaft. This method was rather complicated, an extrashaft (the manoeuvring shaft) quired, the purpose of which was to raisethe roller of the fuel pump from the camshaft during the reversing.

Experiments have been made to simplify the reversing by turning thecamshaft a certain number of degrees, dependent on the reversing angle,then coming out with one controlling cam for each fuel pump, which camhas then in return been furnished with two entrance surfaces or cam faceparts, i. e. one for ahead Working and one for astern working. As aresult of the two cams or cam face parts for ahead and asternrespectively being completely dependent on each other, such controllingcams, however, suffer from the great drawback that an adjustment of thecontrolling cam out of regard to the working in one direction willentail a corresponding adjustment 1 of the cam face part acting for theworking in the opposite direction, which will generally give lessadvantageous conditions for the working in the latter direction if anadjustment is made for obtaining a satisfactory working in the former 1direction.

It has furthermore been proposed to combine one controlling cam of twoor more single cams placed beside one another, one of which beingsecured to the shaft, the other or others being adjustable by beingturned around the axis of the cam. Such a controlling cam is not,however, well. suited for the transmission of large pressures andfurthermore suffers from the drawback that the individual cams cannot besubstituted by others Without first completely disconnecting the shaft.

Thi invention aims at avoiding the drawbacks attached to the knowncontrolling cams while preserving the advantages of effecting thereversgenerally being re-' ing only by a turning (angular shifting) ofthe camshaft.

By the invention is employed a controlling cam of the kind consisting oftwo mutually engaging controlling cam parts which have each its cam facepart, which together form an integral or continuous cam profile, the twocontrollin cam parts being mutually adjustable by turning around theaxis of the controlling cam and able to be maintained in a desiredmutual position, and the purpose of the invention is fulfilled thereby,that the cam face parts on the two controlling cam parts, with a View tothe application of the controlling cam for the control of fuel pumps inreversible internal combustion engines, are constructed or shaped asactive cam face parts, active each for its direction of revolution foractuating the pump plunger for efiecting the pressure stroke of thepump, and that the two controlling cam parts besides are constructed orperformed in such a way, that individually they can be clampedadjustably and so as to be easily changed (i. e. without dismounting thecam shaft itself or neighbouring controlling cams or other parts mountedon the cam shaft) direct or indirect, on the cam shaft, e. g. on a bossfitted on the latter.

The two controlling cam parts according to the invention are suitablymainly shaped as semicircles and at both ends shaped with mutuallycorresponding engagement parts known per so which permit a turning inrelation to each other of the controlling cam parts which further haveoblong holes and a key-shaped axially directed guide intended forengagement with a ringshaped conical recess in a boss on the cam shaft.

According to a further embodiment of the inventicn the two cooperatingengagement parts at the ends of the two controlling cam parts are shapedin such a way that both ends of the controlling cam parts engagemutually with engagement parts, the cam face parts of which are co-axialwith the cam shaft, it being for instance so performed that a projectionor key at each end of the one controlling cam part engages with a grooveor key-way on each end of the other controlling cam part.

The two controlling cam parts may suitably be of the same orapproximately the same size, each of them extending somewhat over of thecircumference, for instance about 200.

With a controlling cam according to the invention an adjustment of eachcam face part may be effected independently of the other cam face part,so that in an engine it is possible to regulate e. g. the time ofignition for the normal direction of rotation of the engine in the bestpossible way according to the conditions under which the en gine is towork without any detrimental effect on the time of ignition when theengine is running 3 in the opposite direction. If it be desired tosubstitute one controlling cam part by another curvature, or during anecessary repair it is possible to make a direct change of thecontrolling cam parts in question, i. e. without disconnecting the earnshaft or the boss on it to which the controlling cam parts have beensecured.

By the said shaping of the controlling cam according to the invention isalso attained the great advantage that an entrance surface is ob--tained on the controlling cam, which surface has the full cam width andwill thus very well be able to take up and transmit the large pressureacting on the entrance surface, in contra-distinction to what is thecase in known controlling cams composed of single cams or discs, wherethe pressure will act more or less partially on the cam roller from thenarrow single cam or disc acting at that moment, and at the transitionfrom one disc to another will be shifted from one side of the rollerface to the other.

The invention is illustrated on the accompanying drawing by anembodiment of a controlling cam consisting of two parts in accordancewith the invention,

Figs 1 showing the two controlling cam parts in side elevation andwithdrawn from each other,

2 the two parts in perspective View and engaged with each other,

Fig. 3 a side elevation of the whole controlling cam, and

Fig. 4 a section along the line IVIV in Fig. 3.

I and 2 designate the two controlling cam parts which have mainly theshape of circular ring parts, and which extend each over about 200 andat the ends by milling out have been furnished with engagement parts 3and 4 respectively, corresponding to each other, the latter of which isa key fitting in a keyway in the part 3. The outer surfaces of theengagement parts 3 and 3 are concentric with the bore of the controllingcam, so that an adjustment of the two controlling cam parts cannotentail any alteration in the smooth transition between the cams or camface parts 5 and 6 respectively shaped on the two controlling cam parts.

In the embodiment shown the controlling cam consists, besides of the twoparts i and 2, of a boss 7 intended for being secured to the cam shaft!5 by means of a key l5 as shown in Figs. 3 and 4. To said boss 7 thetwo controlling cam parts are clamped by a number of screws is], whichare screwed down into tapped holes 8 in the boss 1 and carried throughholes 9 situated in the controlling cam parts, the said holes beingoblong in the direction of the rotation out of regard to theadjustabilit To ensure the reliability of an adjustment of thecontrolling cam parts i and 2 in relation to the boss, each of the saidparts is provided with a cone ll engaging with a corresponding conicalrecess l2 in the boss 7. The oblong holes 9 are covered with segmentsl3, and locking plates 25 are plated outermost over these.

In Fig. 1 a and b designates the points of the cams 5 and 6corresponding to the ignition times for ahead and astern respectively,and as it will be seen, it is possible by said construction to adjustseparately each of these times within rather wide bounds, which may benecessary, as the angle of advance of the cams may vary a great deal inengines of the same type and the same size, and it is amongst otherthings dependent on the number of revolutions.

The invention is not bound to the construction shown and described whichis, as before mentioned, only an embodiment for illustrating theprinciple of the invention.

I claim:

1. A controlling cam comprising two mutually engaging parts shapedsubstantially as semi-circles havin at each end telescoping portions,each of said parts having a cam surface and together forming acontinuous cam profile, each of said parts being adjustable about theaxis of the cam and a boss fixed to a cam shaft upon which said partsare fixed when in adjusted position.

2. A controlling cam comprising two mutually engaging parts ofsubstantially semi-circular configuration having at each. endtelescoping portions, each of said parts. having a cam surface andtogether forming a continuous cam profile, each of said parts beingadjustable about the axis of the cam, a boss keyed to a cam shaft havinga groove therein, a projection on each or" said parts engaging saidgroove and means for looking said projections in said groove.

A controlling cam comprising two mutually engagin parts of substantiallyserni-circular configuration having at each end telescoping portions,each of said parts having a cam surface and together forming acontinuous cam profile, each of said parts being adjustable about theaxis of the cam, a boss keyed to a cam shaft having a groove therein, aprojection on each of said parts engaging said groove, said parts havingoblong holes therein, said boss having threaded holes therein andlocking bolts threaded in said threaded holes extendin through saidoblong holes for Securing said parts to said boss.

4. A controlling cam comprising two mutually engaging parts shapedsubstantially as semi-circles having at each end telescoping portions,each of said parts having a cam surface and together forming acontinuous cam profile, each of said parts bein adjustable about theaxis of the cam and means for fixing said parts to a cam shaft when inadjusted position.

5. A controlling cam comprising two mutually engaging parts shapedsubstantially semi-circular having at each end telescoping portions,each of said parts having a cam surface and together forming acontinuous cam profile, each of said parts being adjustable about theaxis of the cam and a boss fixed to a cam shaft upon which said partswhen in adjusted position are fixed in such a manner that they areexchangeable each per so from the cam shaft without necessitatingdismounting of the boss.

HANS VILI-IELM FLYGEL PEDERSEN.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS

